One common method for printing images on a receiver member is referred to as electrography. In this method, an electrostatic image is formed on a dielectric member by uniformly charging the dielectric member and then discharging selected areas of the uniform charge to yield an image-wise electrostatic charge pattern. Such discharge is typically accomplished by exposing the uniformly charged dielectric member to actinic radiation provided by selectively activating particular light sources in an LED array or a laser device directed at the dielectric member. After the image-wise charge pattern is formed, resin particles are given a charge, substantially opposite the charge pattern on the dielectric member and brought into the vicinity of the dielectric member so as to be attracted to the image-wise charge pattern to develop such pattern into a patterned image.
Thereafter, a suitable receiver member (e.g., a cut sheet of plain bond paper) is brought into juxtaposition with the marking particle developed image-wise charge pattern on the dielectric member. A suitable electric field is applied to transfer the marking particles to the receiver member in the image-wise pattern to form the desired print image on the receiver member. The receiver member is then removed from its operative association with the dielectric member and the marking particle print image is permanently fixed to the receiver member typically using heat, and/or pressure and heat. Multiple layers or marking materials can be overlaid on one receiver, for example, layers of different color particles can be overlaid on one receiver member to form a layer print image on the receiver member after fixing.
In the earlier days of electrographic printing it was desirable to minimize channel formation during fusing. Under most circumstances, channels are considered an objectionable artifact in the print image. In order to improve image quality, and still produce channels a new method of printing has been formulated in U.S. Publication 2009/0142100. In that invention one or more multi-channeled layers are formed using electrographic techniques. There, use of layered printing, includes possible raised images to create channels capable of allowing movement of a fluid, such as an ink or dielectric, to provide a printed article with, among other advantages, a variety of security features on a digitally printed document.
In copending application U.S. Ser. No. 12/608,040 microfluidic structures are used for transporting liquid materials around and mixing in a small device. The liquids are transported to sensors which are used to sense the materials. In microfluidics there is a need though to separate materials as well as mixing materials before the transport to the sensors. In some case it may be necessary to add components to only one component of a samples mixture for better detection.
Gas and liquid chromatography are well known separation techniques. In these techniques an unknown sample of materials are placed in a flowing stream through a channel containing a packing material/stationary phase and allowed to move through the channel. The packing material usually will have some affinity to the materials undergoing testing. Some examples of packing materials are described in Some U.S. Pat. No. 7,557,232. As the unknown materials flow through the channels they are slowed by this affinity to the packing material. Each material in the sample may have a slightly different affinity to the packing material and hence will move through the channel at a different rate. After a specific distance, if there is a difference in the affinity, the materials will have completely separated. A detector can then be used to detect the amount and may identify the material. If the affinities are similar between some components, then one solution is to use a second column of different packing material. Another solution is the reaction of some of the components to allow different affinities.
Microfluidics with laminates is known, as discussed in U.S. Pat. No. 7,553,393. In that patent there is no discussion of the method of manufacture of the channels. The inventors assume one has already generated it and present a lamination method.
Often times, there is also a need to have either multiple sensors to identify materials or to have redundancy. Some materials are difficult to detect by a particular technique. For example colorless materials are difficult to detect by visible absorption while others may have conductivities such that they can not adequately be distinguished from the carrier fluid. In these cases, it would be desirable to route the liquids to multiple sensors.
It would also be desirable to have a cheap configurable channel routing process for separation and detection processes in an inexpensive manner. To allow a small device it should also have the ability to interface well with microfluidic transport and mixing. This invention solves these problems.